11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/net/sunrpc/xprt.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * This is a generic RPC call interface supporting congestion avoidance, 51da177e4SLinus Torvalds * and asynchronous calls. 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * The interface works like this: 81da177e4SLinus Torvalds * 91da177e4SLinus Torvalds * - When a process places a call, it allocates a request slot if 101da177e4SLinus Torvalds * one is available. Otherwise, it sleeps on the backlog queue 111da177e4SLinus Torvalds * (xprt_reserve). 121da177e4SLinus Torvalds * - Next, the caller puts together the RPC message, stuffs it into 1355aa4f58SChuck Lever * the request struct, and calls xprt_transmit(). 1455aa4f58SChuck Lever * - xprt_transmit sends the message and installs the caller on the 1555ae1aabSRicardo Labiaga * transport's wait list. At the same time, if a reply is expected, 1655ae1aabSRicardo Labiaga * it installs a timer that is run after the packet's timeout has 1755ae1aabSRicardo Labiaga * expired. 181da177e4SLinus Torvalds * - When a packet arrives, the data_ready handler walks the list of 1955aa4f58SChuck Lever * pending requests for that transport. If a matching XID is found, the 201da177e4SLinus Torvalds * caller is woken up, and the timer removed. 211da177e4SLinus Torvalds * - When no reply arrives within the timeout interval, the timer is 221da177e4SLinus Torvalds * fired by the kernel and runs xprt_timer(). It either adjusts the 231da177e4SLinus Torvalds * timeout values (minor timeout) or wakes up the caller with a status 241da177e4SLinus Torvalds * of -ETIMEDOUT. 251da177e4SLinus Torvalds * - When the caller receives a notification from RPC that a reply arrived, 261da177e4SLinus Torvalds * it should release the RPC slot, and process the reply. 271da177e4SLinus Torvalds * If the call timed out, it may choose to retry the operation by 281da177e4SLinus Torvalds * adjusting the initial timeout value, and simply calling rpc_call 291da177e4SLinus Torvalds * again. 301da177e4SLinus Torvalds * 311da177e4SLinus Torvalds * Support for async RPC is done through a set of RPC-specific scheduling 321da177e4SLinus Torvalds * primitives that `transparently' work for processes as well as async 331da177e4SLinus Torvalds * tasks that rely on callbacks. 341da177e4SLinus Torvalds * 351da177e4SLinus Torvalds * Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de> 3655aa4f58SChuck Lever * 3755aa4f58SChuck Lever * Transport switch API copyright (C) 2005, Chuck Lever <cel@netapp.com> 381da177e4SLinus Torvalds */ 391da177e4SLinus Torvalds 40a246b010SChuck Lever #include <linux/module.h> 41a246b010SChuck Lever 421da177e4SLinus Torvalds #include <linux/types.h> 43a246b010SChuck Lever #include <linux/interrupt.h> 441da177e4SLinus Torvalds #include <linux/workqueue.h> 45bf3fcf89SChuck Lever #include <linux/net.h> 46ff839970SChuck Lever #include <linux/ktime.h> 471da177e4SLinus Torvalds 48a246b010SChuck Lever #include <linux/sunrpc/clnt.h> 4911c556b3SChuck Lever #include <linux/sunrpc/metrics.h> 50c9acb42eSTrond Myklebust #include <linux/sunrpc/bc_xprt.h> 51fda1bfefSTrond Myklebust #include <linux/rcupdate.h> 521da177e4SLinus Torvalds 533705ad64SJeff Layton #include <trace/events/sunrpc.h> 543705ad64SJeff Layton 5555ae1aabSRicardo Labiaga #include "sunrpc.h" 5655ae1aabSRicardo Labiaga 571da177e4SLinus Torvalds /* 581da177e4SLinus Torvalds * Local variables 591da177e4SLinus Torvalds */ 601da177e4SLinus Torvalds 61f895b252SJeff Layton #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 621da177e4SLinus Torvalds # define RPCDBG_FACILITY RPCDBG_XPRT 631da177e4SLinus Torvalds #endif 641da177e4SLinus Torvalds 651da177e4SLinus Torvalds /* 661da177e4SLinus Torvalds * Local functions 671da177e4SLinus Torvalds */ 6821de0a95STrond Myklebust static void xprt_init(struct rpc_xprt *xprt, struct net *net); 691da177e4SLinus Torvalds static void xprt_request_init(struct rpc_task *, struct rpc_xprt *); 701da177e4SLinus Torvalds static void xprt_connect_status(struct rpc_task *task); 711da177e4SLinus Torvalds static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *); 7229807318SNeil Brown static void __xprt_put_cong(struct rpc_xprt *, struct rpc_rqst *); 734e0038b6STrond Myklebust static void xprt_destroy(struct rpc_xprt *xprt); 741da177e4SLinus Torvalds 755ba03e82SJiri Slaby static DEFINE_SPINLOCK(xprt_list_lock); 7681c098afS\"Talpey, Thomas\ static LIST_HEAD(xprt_list); 7781c098afS\"Talpey, Thomas\ 7812a80469SChuck Lever /** 7981c098afS\"Talpey, Thomas\ * xprt_register_transport - register a transport implementation 8081c098afS\"Talpey, Thomas\ * @transport: transport to register 8181c098afS\"Talpey, Thomas\ * 8281c098afS\"Talpey, Thomas\ * If a transport implementation is loaded as a kernel module, it can 8381c098afS\"Talpey, Thomas\ * call this interface to make itself known to the RPC client. 8481c098afS\"Talpey, Thomas\ * 8581c098afS\"Talpey, Thomas\ * Returns: 8681c098afS\"Talpey, Thomas\ * 0: transport successfully registered 8781c098afS\"Talpey, Thomas\ * -EEXIST: transport already registered 8881c098afS\"Talpey, Thomas\ * -EINVAL: transport module being unloaded 8981c098afS\"Talpey, Thomas\ */ 9081c098afS\"Talpey, Thomas\ int xprt_register_transport(struct xprt_class *transport) 9181c098afS\"Talpey, Thomas\ { 9281c098afS\"Talpey, Thomas\ struct xprt_class *t; 9381c098afS\"Talpey, Thomas\ int result; 9481c098afS\"Talpey, Thomas\ 9581c098afS\"Talpey, Thomas\ result = -EEXIST; 9681c098afS\"Talpey, Thomas\ spin_lock(&xprt_list_lock); 9781c098afS\"Talpey, Thomas\ list_for_each_entry(t, &xprt_list, list) { 9881c098afS\"Talpey, Thomas\ /* don't register the same transport class twice */ 994fa016ebS\"Talpey, Thomas\ if (t->ident == transport->ident) 10081c098afS\"Talpey, Thomas\ goto out; 10181c098afS\"Talpey, Thomas\ } 10281c098afS\"Talpey, Thomas\ 10381c098afS\"Talpey, Thomas\ list_add_tail(&transport->list, &xprt_list); 10481c098afS\"Talpey, Thomas\ printk(KERN_INFO "RPC: Registered %s transport module.\n", 10581c098afS\"Talpey, Thomas\ transport->name); 10681c098afS\"Talpey, Thomas\ result = 0; 10781c098afS\"Talpey, Thomas\ 10881c098afS\"Talpey, Thomas\ out: 10981c098afS\"Talpey, Thomas\ spin_unlock(&xprt_list_lock); 11081c098afS\"Talpey, Thomas\ return result; 11181c098afS\"Talpey, Thomas\ } 11281c098afS\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_register_transport); 11381c098afS\"Talpey, Thomas\ 11481c098afS\"Talpey, Thomas\ /** 11581c098afS\"Talpey, Thomas\ * xprt_unregister_transport - unregister a transport implementation 11665b6e42cSRandy Dunlap * @transport: transport to unregister 11781c098afS\"Talpey, Thomas\ * 11881c098afS\"Talpey, Thomas\ * Returns: 11981c098afS\"Talpey, Thomas\ * 0: transport successfully unregistered 12081c098afS\"Talpey, Thomas\ * -ENOENT: transport never registered 12181c098afS\"Talpey, Thomas\ */ 12281c098afS\"Talpey, Thomas\ int xprt_unregister_transport(struct xprt_class *transport) 12381c098afS\"Talpey, Thomas\ { 12481c098afS\"Talpey, Thomas\ struct xprt_class *t; 12581c098afS\"Talpey, Thomas\ int result; 12681c098afS\"Talpey, Thomas\ 12781c098afS\"Talpey, Thomas\ result = 0; 12881c098afS\"Talpey, Thomas\ spin_lock(&xprt_list_lock); 12981c098afS\"Talpey, Thomas\ list_for_each_entry(t, &xprt_list, list) { 13081c098afS\"Talpey, Thomas\ if (t == transport) { 13181c098afS\"Talpey, Thomas\ printk(KERN_INFO 13281c098afS\"Talpey, Thomas\ "RPC: Unregistered %s transport module.\n", 13381c098afS\"Talpey, Thomas\ transport->name); 13481c098afS\"Talpey, Thomas\ list_del_init(&transport->list); 13581c098afS\"Talpey, Thomas\ goto out; 13681c098afS\"Talpey, Thomas\ } 13781c098afS\"Talpey, Thomas\ } 13881c098afS\"Talpey, Thomas\ result = -ENOENT; 13981c098afS\"Talpey, Thomas\ 14081c098afS\"Talpey, Thomas\ out: 14181c098afS\"Talpey, Thomas\ spin_unlock(&xprt_list_lock); 14281c098afS\"Talpey, Thomas\ return result; 14381c098afS\"Talpey, Thomas\ } 14481c098afS\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_unregister_transport); 14581c098afS\"Talpey, Thomas\ 14681c098afS\"Talpey, Thomas\ /** 147441e3e24STom Talpey * xprt_load_transport - load a transport implementation 148441e3e24STom Talpey * @transport_name: transport to load 149441e3e24STom Talpey * 150441e3e24STom Talpey * Returns: 151441e3e24STom Talpey * 0: transport successfully loaded 152441e3e24STom Talpey * -ENOENT: transport module not available 153441e3e24STom Talpey */ 154441e3e24STom Talpey int xprt_load_transport(const char *transport_name) 155441e3e24STom Talpey { 156441e3e24STom Talpey struct xprt_class *t; 157441e3e24STom Talpey int result; 158441e3e24STom Talpey 159441e3e24STom Talpey result = 0; 160441e3e24STom Talpey spin_lock(&xprt_list_lock); 161441e3e24STom Talpey list_for_each_entry(t, &xprt_list, list) { 162441e3e24STom Talpey if (strcmp(t->name, transport_name) == 0) { 163441e3e24STom Talpey spin_unlock(&xprt_list_lock); 164441e3e24STom Talpey goto out; 165441e3e24STom Talpey } 166441e3e24STom Talpey } 167441e3e24STom Talpey spin_unlock(&xprt_list_lock); 168ef7ffe8fSAlex Riesen result = request_module("xprt%s", transport_name); 169441e3e24STom Talpey out: 170441e3e24STom Talpey return result; 171441e3e24STom Talpey } 172441e3e24STom Talpey EXPORT_SYMBOL_GPL(xprt_load_transport); 173441e3e24STom Talpey 174441e3e24STom Talpey /** 17512a80469SChuck Lever * xprt_reserve_xprt - serialize write access to transports 17612a80469SChuck Lever * @task: task that is requesting access to the transport 177177c27bfSRandy Dunlap * @xprt: pointer to the target transport 17812a80469SChuck Lever * 17912a80469SChuck Lever * This prevents mixing the payload of separate requests, and prevents 18012a80469SChuck Lever * transport connects from colliding with writes. No congestion control 18112a80469SChuck Lever * is provided. 1821da177e4SLinus Torvalds */ 18343cedbf0STrond Myklebust int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task) 1841da177e4SLinus Torvalds { 18512a80469SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 18634006ceeSTrond Myklebust int priority; 18712a80469SChuck Lever 18812a80469SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { 18912a80469SChuck Lever if (task == xprt->snd_task) 19012a80469SChuck Lever return 1; 19112a80469SChuck Lever goto out_sleep; 19212a80469SChuck Lever } 19312a80469SChuck Lever xprt->snd_task = task; 19492551948STrond Myklebust if (req != NULL) 19512a80469SChuck Lever req->rq_ntrans++; 1964d4a76f3Sj223yang@asset.uwaterloo.ca 19712a80469SChuck Lever return 1; 19812a80469SChuck Lever 19912a80469SChuck Lever out_sleep: 20046121cf7SChuck Lever dprintk("RPC: %5u failed to lock transport %p\n", 20112a80469SChuck Lever task->tk_pid, xprt); 20212a80469SChuck Lever task->tk_timeout = 0; 20312a80469SChuck Lever task->tk_status = -EAGAIN; 20434006ceeSTrond Myklebust if (req == NULL) 20534006ceeSTrond Myklebust priority = RPC_PRIORITY_LOW; 20634006ceeSTrond Myklebust else if (!req->rq_ntrans) 20734006ceeSTrond Myklebust priority = RPC_PRIORITY_NORMAL; 20812a80469SChuck Lever else 20934006ceeSTrond Myklebust priority = RPC_PRIORITY_HIGH; 21034006ceeSTrond Myklebust rpc_sleep_on_priority(&xprt->sending, task, NULL, priority); 21112a80469SChuck Lever return 0; 21212a80469SChuck Lever } 21312444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_reserve_xprt); 21412a80469SChuck Lever 215632e3bdcSTrond Myklebust static void xprt_clear_locked(struct rpc_xprt *xprt) 216632e3bdcSTrond Myklebust { 217632e3bdcSTrond Myklebust xprt->snd_task = NULL; 218d19751e7STrond Myklebust if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state)) { 2194e857c58SPeter Zijlstra smp_mb__before_atomic(); 220632e3bdcSTrond Myklebust clear_bit(XPRT_LOCKED, &xprt->state); 2214e857c58SPeter Zijlstra smp_mb__after_atomic(); 222632e3bdcSTrond Myklebust } else 22340a5f1b1STrond Myklebust queue_work(xprtiod_workqueue, &xprt->task_cleanup); 224632e3bdcSTrond Myklebust } 225632e3bdcSTrond Myklebust 22612a80469SChuck Lever /* 22712a80469SChuck Lever * xprt_reserve_xprt_cong - serialize write access to transports 22812a80469SChuck Lever * @task: task that is requesting access to the transport 22912a80469SChuck Lever * 23012a80469SChuck Lever * Same as xprt_reserve_xprt, but Van Jacobson congestion control is 23112a80469SChuck Lever * integrated into the decision of whether a request is allowed to be 23212a80469SChuck Lever * woken up and given access to the transport. 23312a80469SChuck Lever */ 23443cedbf0STrond Myklebust int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) 23512a80469SChuck Lever { 2361da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 23734006ceeSTrond Myklebust int priority; 2381da177e4SLinus Torvalds 2392226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { 2401da177e4SLinus Torvalds if (task == xprt->snd_task) 2411da177e4SLinus Torvalds return 1; 2421da177e4SLinus Torvalds goto out_sleep; 2431da177e4SLinus Torvalds } 24443cedbf0STrond Myklebust if (req == NULL) { 24543cedbf0STrond Myklebust xprt->snd_task = task; 24643cedbf0STrond Myklebust return 1; 24743cedbf0STrond Myklebust } 24812a80469SChuck Lever if (__xprt_get_cong(xprt, task)) { 2491da177e4SLinus Torvalds xprt->snd_task = task; 2501da177e4SLinus Torvalds req->rq_ntrans++; 2511da177e4SLinus Torvalds return 1; 2521da177e4SLinus Torvalds } 253632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 2541da177e4SLinus Torvalds out_sleep: 25529807318SNeil Brown if (req) 25629807318SNeil Brown __xprt_put_cong(xprt, req); 25746121cf7SChuck Lever dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt); 2581da177e4SLinus Torvalds task->tk_timeout = 0; 2591da177e4SLinus Torvalds task->tk_status = -EAGAIN; 26034006ceeSTrond Myklebust if (req == NULL) 26134006ceeSTrond Myklebust priority = RPC_PRIORITY_LOW; 26234006ceeSTrond Myklebust else if (!req->rq_ntrans) 26334006ceeSTrond Myklebust priority = RPC_PRIORITY_NORMAL; 2641da177e4SLinus Torvalds else 26534006ceeSTrond Myklebust priority = RPC_PRIORITY_HIGH; 26634006ceeSTrond Myklebust rpc_sleep_on_priority(&xprt->sending, task, NULL, priority); 2671da177e4SLinus Torvalds return 0; 2681da177e4SLinus Torvalds } 26912444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong); 2701da177e4SLinus Torvalds 27112a80469SChuck Lever static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) 2721da177e4SLinus Torvalds { 2731da177e4SLinus Torvalds int retval; 2741da177e4SLinus Torvalds 2754a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 27643cedbf0STrond Myklebust retval = xprt->ops->reserve_xprt(xprt, task); 2774a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 2781da177e4SLinus Torvalds return retval; 2791da177e4SLinus Torvalds } 2801da177e4SLinus Torvalds 281961a828dSTrond Myklebust static bool __xprt_lock_write_func(struct rpc_task *task, void *data) 2821da177e4SLinus Torvalds { 283961a828dSTrond Myklebust struct rpc_xprt *xprt = data; 28449e9a890SChuck Lever struct rpc_rqst *req; 28549e9a890SChuck Lever 28649e9a890SChuck Lever req = task->tk_rqstp; 28749e9a890SChuck Lever xprt->snd_task = task; 28892551948STrond Myklebust if (req) 28949e9a890SChuck Lever req->rq_ntrans++; 290961a828dSTrond Myklebust return true; 291961a828dSTrond Myklebust } 292961a828dSTrond Myklebust 293961a828dSTrond Myklebust static void __xprt_lock_write_next(struct rpc_xprt *xprt) 294961a828dSTrond Myklebust { 295961a828dSTrond Myklebust if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 29649e9a890SChuck Lever return; 29749e9a890SChuck Lever 298f1dc237cSTrond Myklebust if (rpc_wake_up_first_on_wq(xprtiod_workqueue, &xprt->sending, 299f1dc237cSTrond Myklebust __xprt_lock_write_func, xprt)) 300961a828dSTrond Myklebust return; 301632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 30249e9a890SChuck Lever } 30349e9a890SChuck Lever 304961a828dSTrond Myklebust static bool __xprt_lock_write_cong_func(struct rpc_task *task, void *data) 30549e9a890SChuck Lever { 306961a828dSTrond Myklebust struct rpc_xprt *xprt = data; 30743cedbf0STrond Myklebust struct rpc_rqst *req; 3081da177e4SLinus Torvalds 30943cedbf0STrond Myklebust req = task->tk_rqstp; 31043cedbf0STrond Myklebust if (req == NULL) { 3111da177e4SLinus Torvalds xprt->snd_task = task; 312961a828dSTrond Myklebust return true; 31343cedbf0STrond Myklebust } 31443cedbf0STrond Myklebust if (__xprt_get_cong(xprt, task)) { 31543cedbf0STrond Myklebust xprt->snd_task = task; 3161da177e4SLinus Torvalds req->rq_ntrans++; 317961a828dSTrond Myklebust return true; 3181da177e4SLinus Torvalds } 319961a828dSTrond Myklebust return false; 320961a828dSTrond Myklebust } 321961a828dSTrond Myklebust 322961a828dSTrond Myklebust static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt) 323961a828dSTrond Myklebust { 324961a828dSTrond Myklebust if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 325961a828dSTrond Myklebust return; 326961a828dSTrond Myklebust if (RPCXPRT_CONGESTED(xprt)) 327961a828dSTrond Myklebust goto out_unlock; 328f1dc237cSTrond Myklebust if (rpc_wake_up_first_on_wq(xprtiod_workqueue, &xprt->sending, 329f1dc237cSTrond Myklebust __xprt_lock_write_cong_func, xprt)) 330961a828dSTrond Myklebust return; 3311da177e4SLinus Torvalds out_unlock: 332632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 3331da177e4SLinus Torvalds } 3341da177e4SLinus Torvalds 3350695314eSTrond Myklebust static void xprt_task_clear_bytes_sent(struct rpc_task *task) 3360695314eSTrond Myklebust { 3370695314eSTrond Myklebust if (task != NULL) { 3380695314eSTrond Myklebust struct rpc_rqst *req = task->tk_rqstp; 3390695314eSTrond Myklebust if (req != NULL) 3400695314eSTrond Myklebust req->rq_bytes_sent = 0; 3410695314eSTrond Myklebust } 3420695314eSTrond Myklebust } 3430695314eSTrond Myklebust 34449e9a890SChuck Lever /** 34549e9a890SChuck Lever * xprt_release_xprt - allow other requests to use a transport 34649e9a890SChuck Lever * @xprt: transport with other tasks potentially waiting 34749e9a890SChuck Lever * @task: task that is releasing access to the transport 34849e9a890SChuck Lever * 34949e9a890SChuck Lever * Note that "task" can be NULL. No congestion control is provided. 3501da177e4SLinus Torvalds */ 35149e9a890SChuck Lever void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) 3521da177e4SLinus Torvalds { 3531da177e4SLinus Torvalds if (xprt->snd_task == task) { 3540695314eSTrond Myklebust xprt_task_clear_bytes_sent(task); 355632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 3561da177e4SLinus Torvalds __xprt_lock_write_next(xprt); 3571da177e4SLinus Torvalds } 3581da177e4SLinus Torvalds } 35912444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_release_xprt); 3601da177e4SLinus Torvalds 36149e9a890SChuck Lever /** 36249e9a890SChuck Lever * xprt_release_xprt_cong - allow other requests to use a transport 36349e9a890SChuck Lever * @xprt: transport with other tasks potentially waiting 36449e9a890SChuck Lever * @task: task that is releasing access to the transport 36549e9a890SChuck Lever * 36649e9a890SChuck Lever * Note that "task" can be NULL. Another task is awoken to use the 36749e9a890SChuck Lever * transport if the transport's congestion window allows it. 36849e9a890SChuck Lever */ 36949e9a890SChuck Lever void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) 37049e9a890SChuck Lever { 37149e9a890SChuck Lever if (xprt->snd_task == task) { 3720695314eSTrond Myklebust xprt_task_clear_bytes_sent(task); 373632e3bdcSTrond Myklebust xprt_clear_locked(xprt); 37449e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 37549e9a890SChuck Lever } 37649e9a890SChuck Lever } 37712444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_release_xprt_cong); 37849e9a890SChuck Lever 37949e9a890SChuck Lever static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) 3801da177e4SLinus Torvalds { 3814a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 38249e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 3834a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 3841da177e4SLinus Torvalds } 3851da177e4SLinus Torvalds 3861da177e4SLinus Torvalds /* 3871da177e4SLinus Torvalds * Van Jacobson congestion avoidance. Check if the congestion window 3881da177e4SLinus Torvalds * overflowed. Put the task to sleep if this is the case. 3891da177e4SLinus Torvalds */ 3901da177e4SLinus Torvalds static int 3911da177e4SLinus Torvalds __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task) 3921da177e4SLinus Torvalds { 3931da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 3941da177e4SLinus Torvalds 3951da177e4SLinus Torvalds if (req->rq_cong) 3961da177e4SLinus Torvalds return 1; 39746121cf7SChuck Lever dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n", 3981da177e4SLinus Torvalds task->tk_pid, xprt->cong, xprt->cwnd); 3991da177e4SLinus Torvalds if (RPCXPRT_CONGESTED(xprt)) 4001da177e4SLinus Torvalds return 0; 4011da177e4SLinus Torvalds req->rq_cong = 1; 4021da177e4SLinus Torvalds xprt->cong += RPC_CWNDSCALE; 4031da177e4SLinus Torvalds return 1; 4041da177e4SLinus Torvalds } 4051da177e4SLinus Torvalds 4061da177e4SLinus Torvalds /* 4071da177e4SLinus Torvalds * Adjust the congestion window, and wake up the next task 4081da177e4SLinus Torvalds * that has been sleeping due to congestion 4091da177e4SLinus Torvalds */ 4101da177e4SLinus Torvalds static void 4111da177e4SLinus Torvalds __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) 4121da177e4SLinus Torvalds { 4131da177e4SLinus Torvalds if (!req->rq_cong) 4141da177e4SLinus Torvalds return; 4151da177e4SLinus Torvalds req->rq_cong = 0; 4161da177e4SLinus Torvalds xprt->cong -= RPC_CWNDSCALE; 41749e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 4181da177e4SLinus Torvalds } 4191da177e4SLinus Torvalds 42046c0ee8bSChuck Lever /** 421a58dd398SChuck Lever * xprt_release_rqst_cong - housekeeping when request is complete 422a58dd398SChuck Lever * @task: RPC request that recently completed 423a58dd398SChuck Lever * 424a58dd398SChuck Lever * Useful for transports that require congestion control. 425a58dd398SChuck Lever */ 426a58dd398SChuck Lever void xprt_release_rqst_cong(struct rpc_task *task) 427a58dd398SChuck Lever { 428a4f0835cSTrond Myklebust struct rpc_rqst *req = task->tk_rqstp; 429a4f0835cSTrond Myklebust 430a4f0835cSTrond Myklebust __xprt_put_cong(req->rq_xprt, req); 431a58dd398SChuck Lever } 43212444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_release_rqst_cong); 433a58dd398SChuck Lever 434a58dd398SChuck Lever /** 43546c0ee8bSChuck Lever * xprt_adjust_cwnd - adjust transport congestion window 4366a24dfb6STrond Myklebust * @xprt: pointer to xprt 43746c0ee8bSChuck Lever * @task: recently completed RPC request used to adjust window 43846c0ee8bSChuck Lever * @result: result code of completed RPC request 43946c0ee8bSChuck Lever * 4404f4cf5adSChuck Lever * The transport code maintains an estimate on the maximum number of out- 4414f4cf5adSChuck Lever * standing RPC requests, using a smoothed version of the congestion 4424f4cf5adSChuck Lever * avoidance implemented in 44BSD. This is basically the Van Jacobson 4434f4cf5adSChuck Lever * congestion algorithm: If a retransmit occurs, the congestion window is 4444f4cf5adSChuck Lever * halved; otherwise, it is incremented by 1/cwnd when 4454f4cf5adSChuck Lever * 4464f4cf5adSChuck Lever * - a reply is received and 4474f4cf5adSChuck Lever * - a full number of requests are outstanding and 4484f4cf5adSChuck Lever * - the congestion window hasn't been updated recently. 4491da177e4SLinus Torvalds */ 4506a24dfb6STrond Myklebust void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result) 4511da177e4SLinus Torvalds { 45246c0ee8bSChuck Lever struct rpc_rqst *req = task->tk_rqstp; 45346c0ee8bSChuck Lever unsigned long cwnd = xprt->cwnd; 4541da177e4SLinus Torvalds 4551da177e4SLinus Torvalds if (result >= 0 && cwnd <= xprt->cong) { 4561da177e4SLinus Torvalds /* The (cwnd >> 1) term makes sure 4571da177e4SLinus Torvalds * the result gets rounded properly. */ 4581da177e4SLinus Torvalds cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd; 4591da177e4SLinus Torvalds if (cwnd > RPC_MAXCWND(xprt)) 4601da177e4SLinus Torvalds cwnd = RPC_MAXCWND(xprt); 46149e9a890SChuck Lever __xprt_lock_write_next_cong(xprt); 4621da177e4SLinus Torvalds } else if (result == -ETIMEDOUT) { 4631da177e4SLinus Torvalds cwnd >>= 1; 4641da177e4SLinus Torvalds if (cwnd < RPC_CWNDSCALE) 4651da177e4SLinus Torvalds cwnd = RPC_CWNDSCALE; 4661da177e4SLinus Torvalds } 4671da177e4SLinus Torvalds dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n", 4681da177e4SLinus Torvalds xprt->cong, xprt->cwnd, cwnd); 4691da177e4SLinus Torvalds xprt->cwnd = cwnd; 47046c0ee8bSChuck Lever __xprt_put_cong(xprt, req); 4711da177e4SLinus Torvalds } 47212444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_adjust_cwnd); 4731da177e4SLinus Torvalds 47444fbac22SChuck Lever /** 47544fbac22SChuck Lever * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue 47644fbac22SChuck Lever * @xprt: transport with waiting tasks 47744fbac22SChuck Lever * @status: result code to plant in each task before waking it 47844fbac22SChuck Lever * 47944fbac22SChuck Lever */ 48044fbac22SChuck Lever void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status) 48144fbac22SChuck Lever { 48244fbac22SChuck Lever if (status < 0) 48344fbac22SChuck Lever rpc_wake_up_status(&xprt->pending, status); 48444fbac22SChuck Lever else 48544fbac22SChuck Lever rpc_wake_up(&xprt->pending); 48644fbac22SChuck Lever } 48712444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks); 48844fbac22SChuck Lever 489c7b2cae8SChuck Lever /** 490c7b2cae8SChuck Lever * xprt_wait_for_buffer_space - wait for transport output buffer to clear 491c7b2cae8SChuck Lever * @task: task to be put to sleep 4920b80ae42SRandy Dunlap * @action: function pointer to be executed after wait 493a9a6b52eSTrond Myklebust * 494a9a6b52eSTrond Myklebust * Note that we only set the timer for the case of RPC_IS_SOFT(), since 495a9a6b52eSTrond Myklebust * we don't in general want to force a socket disconnection due to 496a9a6b52eSTrond Myklebust * an incomplete RPC call transmission. 497c7b2cae8SChuck Lever */ 498b6ddf64fSTrond Myklebust void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action) 499c7b2cae8SChuck Lever { 500c7b2cae8SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 501c7b2cae8SChuck Lever struct rpc_xprt *xprt = req->rq_xprt; 502c7b2cae8SChuck Lever 503a9a6b52eSTrond Myklebust task->tk_timeout = RPC_IS_SOFT(task) ? req->rq_timeout : 0; 504b6ddf64fSTrond Myklebust rpc_sleep_on(&xprt->pending, task, action); 505c7b2cae8SChuck Lever } 50612444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space); 507c7b2cae8SChuck Lever 508c7b2cae8SChuck Lever /** 509c7b2cae8SChuck Lever * xprt_write_space - wake the task waiting for transport output buffer space 510c7b2cae8SChuck Lever * @xprt: transport with waiting tasks 511c7b2cae8SChuck Lever * 512c7b2cae8SChuck Lever * Can be called in a soft IRQ context, so xprt_write_space never sleeps. 513c7b2cae8SChuck Lever */ 514c7b2cae8SChuck Lever void xprt_write_space(struct rpc_xprt *xprt) 515c7b2cae8SChuck Lever { 516c7b2cae8SChuck Lever spin_lock_bh(&xprt->transport_lock); 517c7b2cae8SChuck Lever if (xprt->snd_task) { 51846121cf7SChuck Lever dprintk("RPC: write space: waking waiting task on " 51946121cf7SChuck Lever "xprt %p\n", xprt); 520fda13939STrond Myklebust rpc_wake_up_queued_task(&xprt->pending, xprt->snd_task); 521c7b2cae8SChuck Lever } 522c7b2cae8SChuck Lever spin_unlock_bh(&xprt->transport_lock); 523c7b2cae8SChuck Lever } 52412444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_write_space); 525c7b2cae8SChuck Lever 526fe3aca29SChuck Lever /** 527fe3aca29SChuck Lever * xprt_set_retrans_timeout_def - set a request's retransmit timeout 528fe3aca29SChuck Lever * @task: task whose timeout is to be set 529fe3aca29SChuck Lever * 530fe3aca29SChuck Lever * Set a request's retransmit timeout based on the transport's 531fe3aca29SChuck Lever * default timeout parameters. Used by transports that don't adjust 532fe3aca29SChuck Lever * the retransmit timeout based on round-trip time estimation. 533fe3aca29SChuck Lever */ 534fe3aca29SChuck Lever void xprt_set_retrans_timeout_def(struct rpc_task *task) 535fe3aca29SChuck Lever { 536fe3aca29SChuck Lever task->tk_timeout = task->tk_rqstp->rq_timeout; 537fe3aca29SChuck Lever } 53812444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def); 539fe3aca29SChuck Lever 5402c53040fSBen Hutchings /** 541fe3aca29SChuck Lever * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout 542fe3aca29SChuck Lever * @task: task whose timeout is to be set 543fe3aca29SChuck Lever * 544fe3aca29SChuck Lever * Set a request's retransmit timeout using the RTT estimator. 545fe3aca29SChuck Lever */ 546fe3aca29SChuck Lever void xprt_set_retrans_timeout_rtt(struct rpc_task *task) 547fe3aca29SChuck Lever { 548fe3aca29SChuck Lever int timer = task->tk_msg.rpc_proc->p_timer; 549ba7392bbSTrond Myklebust struct rpc_clnt *clnt = task->tk_client; 550ba7392bbSTrond Myklebust struct rpc_rtt *rtt = clnt->cl_rtt; 551fe3aca29SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 552ba7392bbSTrond Myklebust unsigned long max_timeout = clnt->cl_timeout->to_maxval; 553fe3aca29SChuck Lever 554fe3aca29SChuck Lever task->tk_timeout = rpc_calc_rto(rtt, timer); 555fe3aca29SChuck Lever task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries; 556fe3aca29SChuck Lever if (task->tk_timeout > max_timeout || task->tk_timeout == 0) 557fe3aca29SChuck Lever task->tk_timeout = max_timeout; 558fe3aca29SChuck Lever } 55912444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt); 560fe3aca29SChuck Lever 5611da177e4SLinus Torvalds static void xprt_reset_majortimeo(struct rpc_rqst *req) 5621da177e4SLinus Torvalds { 563ba7392bbSTrond Myklebust const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; 5641da177e4SLinus Torvalds 5651da177e4SLinus Torvalds req->rq_majortimeo = req->rq_timeout; 5661da177e4SLinus Torvalds if (to->to_exponential) 5671da177e4SLinus Torvalds req->rq_majortimeo <<= to->to_retries; 5681da177e4SLinus Torvalds else 5691da177e4SLinus Torvalds req->rq_majortimeo += to->to_increment * to->to_retries; 5701da177e4SLinus Torvalds if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0) 5711da177e4SLinus Torvalds req->rq_majortimeo = to->to_maxval; 5721da177e4SLinus Torvalds req->rq_majortimeo += jiffies; 5731da177e4SLinus Torvalds } 5741da177e4SLinus Torvalds 5759903cd1cSChuck Lever /** 5769903cd1cSChuck Lever * xprt_adjust_timeout - adjust timeout values for next retransmit 5779903cd1cSChuck Lever * @req: RPC request containing parameters to use for the adjustment 5789903cd1cSChuck Lever * 5791da177e4SLinus Torvalds */ 5801da177e4SLinus Torvalds int xprt_adjust_timeout(struct rpc_rqst *req) 5811da177e4SLinus Torvalds { 5821da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 583ba7392bbSTrond Myklebust const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; 5841da177e4SLinus Torvalds int status = 0; 5851da177e4SLinus Torvalds 5861da177e4SLinus Torvalds if (time_before(jiffies, req->rq_majortimeo)) { 5871da177e4SLinus Torvalds if (to->to_exponential) 5881da177e4SLinus Torvalds req->rq_timeout <<= 1; 5891da177e4SLinus Torvalds else 5901da177e4SLinus Torvalds req->rq_timeout += to->to_increment; 5911da177e4SLinus Torvalds if (to->to_maxval && req->rq_timeout >= to->to_maxval) 5921da177e4SLinus Torvalds req->rq_timeout = to->to_maxval; 5931da177e4SLinus Torvalds req->rq_retries++; 5941da177e4SLinus Torvalds } else { 5951da177e4SLinus Torvalds req->rq_timeout = to->to_initval; 5961da177e4SLinus Torvalds req->rq_retries = 0; 5971da177e4SLinus Torvalds xprt_reset_majortimeo(req); 5981da177e4SLinus Torvalds /* Reset the RTT counters == "slow start" */ 5994a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 6001da177e4SLinus Torvalds rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval); 6014a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 6021da177e4SLinus Torvalds status = -ETIMEDOUT; 6031da177e4SLinus Torvalds } 6041da177e4SLinus Torvalds 6051da177e4SLinus Torvalds if (req->rq_timeout == 0) { 6061da177e4SLinus Torvalds printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n"); 6071da177e4SLinus Torvalds req->rq_timeout = 5 * HZ; 6081da177e4SLinus Torvalds } 6091da177e4SLinus Torvalds return status; 6101da177e4SLinus Torvalds } 6111da177e4SLinus Torvalds 61265f27f38SDavid Howells static void xprt_autoclose(struct work_struct *work) 6131da177e4SLinus Torvalds { 61465f27f38SDavid Howells struct rpc_xprt *xprt = 61565f27f38SDavid Howells container_of(work, struct rpc_xprt, task_cleanup); 6161da177e4SLinus Torvalds 61766af1e55STrond Myklebust clear_bit(XPRT_CLOSE_WAIT, &xprt->state); 6184876cc77STrond Myklebust xprt->ops->close(xprt); 6191da177e4SLinus Torvalds xprt_release_write(xprt, NULL); 62079234c3dSTrond Myklebust wake_up_bit(&xprt->state, XPRT_LOCKED); 6211da177e4SLinus Torvalds } 6221da177e4SLinus Torvalds 6239903cd1cSChuck Lever /** 62462da3b24STrond Myklebust * xprt_disconnect_done - mark a transport as disconnected 6259903cd1cSChuck Lever * @xprt: transport to flag for disconnect 6269903cd1cSChuck Lever * 6271da177e4SLinus Torvalds */ 62862da3b24STrond Myklebust void xprt_disconnect_done(struct rpc_xprt *xprt) 6291da177e4SLinus Torvalds { 6301da177e4SLinus Torvalds dprintk("RPC: disconnected transport %p\n", xprt); 6314a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 6321da177e4SLinus Torvalds xprt_clear_connected(xprt); 6332a491991STrond Myklebust xprt_wake_pending_tasks(xprt, -EAGAIN); 6344a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 6351da177e4SLinus Torvalds } 63662da3b24STrond Myklebust EXPORT_SYMBOL_GPL(xprt_disconnect_done); 6371da177e4SLinus Torvalds 63866af1e55STrond Myklebust /** 63966af1e55STrond Myklebust * xprt_force_disconnect - force a transport to disconnect 64066af1e55STrond Myklebust * @xprt: transport to disconnect 64166af1e55STrond Myklebust * 64266af1e55STrond Myklebust */ 64366af1e55STrond Myklebust void xprt_force_disconnect(struct rpc_xprt *xprt) 64466af1e55STrond Myklebust { 64566af1e55STrond Myklebust /* Don't race with the test_bit() in xprt_clear_locked() */ 64666af1e55STrond Myklebust spin_lock_bh(&xprt->transport_lock); 64766af1e55STrond Myklebust set_bit(XPRT_CLOSE_WAIT, &xprt->state); 64866af1e55STrond Myklebust /* Try to schedule an autoclose RPC call */ 64966af1e55STrond Myklebust if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) 65040a5f1b1STrond Myklebust queue_work(xprtiod_workqueue, &xprt->task_cleanup); 6512a491991STrond Myklebust xprt_wake_pending_tasks(xprt, -EAGAIN); 65266af1e55STrond Myklebust spin_unlock_bh(&xprt->transport_lock); 65366af1e55STrond Myklebust } 65466af1e55STrond Myklebust 6557c1d71cfSTrond Myklebust /** 6567c1d71cfSTrond Myklebust * xprt_conditional_disconnect - force a transport to disconnect 6577c1d71cfSTrond Myklebust * @xprt: transport to disconnect 6587c1d71cfSTrond Myklebust * @cookie: 'connection cookie' 6597c1d71cfSTrond Myklebust * 6607c1d71cfSTrond Myklebust * This attempts to break the connection if and only if 'cookie' matches 6617c1d71cfSTrond Myklebust * the current transport 'connection cookie'. It ensures that we don't 6627c1d71cfSTrond Myklebust * try to break the connection more than once when we need to retransmit 6637c1d71cfSTrond Myklebust * a batch of RPC requests. 6647c1d71cfSTrond Myklebust * 6657c1d71cfSTrond Myklebust */ 6667c1d71cfSTrond Myklebust void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie) 6677c1d71cfSTrond Myklebust { 6687c1d71cfSTrond Myklebust /* Don't race with the test_bit() in xprt_clear_locked() */ 6697c1d71cfSTrond Myklebust spin_lock_bh(&xprt->transport_lock); 6707c1d71cfSTrond Myklebust if (cookie != xprt->connect_cookie) 6717c1d71cfSTrond Myklebust goto out; 6727c1d71cfSTrond Myklebust if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt)) 6737c1d71cfSTrond Myklebust goto out; 6747c1d71cfSTrond Myklebust set_bit(XPRT_CLOSE_WAIT, &xprt->state); 6757c1d71cfSTrond Myklebust /* Try to schedule an autoclose RPC call */ 6767c1d71cfSTrond Myklebust if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) 67740a5f1b1STrond Myklebust queue_work(xprtiod_workqueue, &xprt->task_cleanup); 6782a491991STrond Myklebust xprt_wake_pending_tasks(xprt, -EAGAIN); 6797c1d71cfSTrond Myklebust out: 6807c1d71cfSTrond Myklebust spin_unlock_bh(&xprt->transport_lock); 6817c1d71cfSTrond Myklebust } 6827c1d71cfSTrond Myklebust 683ad3331acSTrond Myklebust static bool 684ad3331acSTrond Myklebust xprt_has_timer(const struct rpc_xprt *xprt) 685ad3331acSTrond Myklebust { 686ad3331acSTrond Myklebust return xprt->idle_timeout != 0; 687ad3331acSTrond Myklebust } 688ad3331acSTrond Myklebust 689ad3331acSTrond Myklebust static void 690ad3331acSTrond Myklebust xprt_schedule_autodisconnect(struct rpc_xprt *xprt) 691ad3331acSTrond Myklebust __must_hold(&xprt->transport_lock) 692ad3331acSTrond Myklebust { 693ad3331acSTrond Myklebust if (list_empty(&xprt->recv) && xprt_has_timer(xprt)) 694ad3331acSTrond Myklebust mod_timer(&xprt->timer, xprt->last_used + xprt->idle_timeout); 695ad3331acSTrond Myklebust } 696ad3331acSTrond Myklebust 6971da177e4SLinus Torvalds static void 6981da177e4SLinus Torvalds xprt_init_autodisconnect(unsigned long data) 6991da177e4SLinus Torvalds { 7001da177e4SLinus Torvalds struct rpc_xprt *xprt = (struct rpc_xprt *)data; 7011da177e4SLinus Torvalds 7024a0f8c04SChuck Lever spin_lock(&xprt->transport_lock); 703d19751e7STrond Myklebust if (!list_empty(&xprt->recv)) 7041da177e4SLinus Torvalds goto out_abort; 705ad3331acSTrond Myklebust /* Reset xprt->last_used to avoid connect/autodisconnect cycling */ 706ad3331acSTrond Myklebust xprt->last_used = jiffies; 7072226feb6SChuck Lever if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) 7081da177e4SLinus Torvalds goto out_abort; 7094a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 71040a5f1b1STrond Myklebust queue_work(xprtiod_workqueue, &xprt->task_cleanup); 7111da177e4SLinus Torvalds return; 7121da177e4SLinus Torvalds out_abort: 7134a0f8c04SChuck Lever spin_unlock(&xprt->transport_lock); 7141da177e4SLinus Torvalds } 7151da177e4SLinus Torvalds 716718ba5b8STrond Myklebust bool xprt_lock_connect(struct rpc_xprt *xprt, 717718ba5b8STrond Myklebust struct rpc_task *task, 718718ba5b8STrond Myklebust void *cookie) 719718ba5b8STrond Myklebust { 720718ba5b8STrond Myklebust bool ret = false; 721718ba5b8STrond Myklebust 722718ba5b8STrond Myklebust spin_lock_bh(&xprt->transport_lock); 723718ba5b8STrond Myklebust if (!test_bit(XPRT_LOCKED, &xprt->state)) 724718ba5b8STrond Myklebust goto out; 725718ba5b8STrond Myklebust if (xprt->snd_task != task) 726718ba5b8STrond Myklebust goto out; 7270695314eSTrond Myklebust xprt_task_clear_bytes_sent(task); 728718ba5b8STrond Myklebust xprt->snd_task = cookie; 729718ba5b8STrond Myklebust ret = true; 730718ba5b8STrond Myklebust out: 731718ba5b8STrond Myklebust spin_unlock_bh(&xprt->transport_lock); 732718ba5b8STrond Myklebust return ret; 733718ba5b8STrond Myklebust } 734718ba5b8STrond Myklebust 735718ba5b8STrond Myklebust void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie) 736718ba5b8STrond Myklebust { 737718ba5b8STrond Myklebust spin_lock_bh(&xprt->transport_lock); 738718ba5b8STrond Myklebust if (xprt->snd_task != cookie) 739718ba5b8STrond Myklebust goto out; 740718ba5b8STrond Myklebust if (!test_bit(XPRT_LOCKED, &xprt->state)) 741718ba5b8STrond Myklebust goto out; 742718ba5b8STrond Myklebust xprt->snd_task =NULL; 743718ba5b8STrond Myklebust xprt->ops->release_xprt(xprt, NULL); 744ad3331acSTrond Myklebust xprt_schedule_autodisconnect(xprt); 745718ba5b8STrond Myklebust out: 746718ba5b8STrond Myklebust spin_unlock_bh(&xprt->transport_lock); 74779234c3dSTrond Myklebust wake_up_bit(&xprt->state, XPRT_LOCKED); 748718ba5b8STrond Myklebust } 749718ba5b8STrond Myklebust 7509903cd1cSChuck Lever /** 7519903cd1cSChuck Lever * xprt_connect - schedule a transport connect operation 7529903cd1cSChuck Lever * @task: RPC task that is requesting the connect 7531da177e4SLinus Torvalds * 7541da177e4SLinus Torvalds */ 7551da177e4SLinus Torvalds void xprt_connect(struct rpc_task *task) 7561da177e4SLinus Torvalds { 757ad2368d6STrond Myklebust struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; 7581da177e4SLinus Torvalds 75946121cf7SChuck Lever dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid, 7601da177e4SLinus Torvalds xprt, (xprt_connected(xprt) ? "is" : "is not")); 7611da177e4SLinus Torvalds 762ec739ef0SChuck Lever if (!xprt_bound(xprt)) { 76301d37c42STrond Myklebust task->tk_status = -EAGAIN; 7641da177e4SLinus Torvalds return; 7651da177e4SLinus Torvalds } 7661da177e4SLinus Torvalds if (!xprt_lock_write(xprt, task)) 7671da177e4SLinus Torvalds return; 768feb8ca37STrond Myklebust 769feb8ca37STrond Myklebust if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state)) 770feb8ca37STrond Myklebust xprt->ops->close(xprt); 771feb8ca37STrond Myklebust 772718ba5b8STrond Myklebust if (!xprt_connected(xprt)) { 7731da177e4SLinus Torvalds task->tk_rqstp->rq_bytes_sent = 0; 774a8ce4a8fSTrond Myklebust task->tk_timeout = task->tk_rqstp->rq_timeout; 7755d00837bSTrond Myklebust rpc_sleep_on(&xprt->pending, task, xprt_connect_status); 7760b9e7943STrond Myklebust 7770b9e7943STrond Myklebust if (test_bit(XPRT_CLOSING, &xprt->state)) 7780b9e7943STrond Myklebust return; 7790b9e7943STrond Myklebust if (xprt_test_and_set_connecting(xprt)) 7800b9e7943STrond Myklebust return; 781262ca07dSChuck Lever xprt->stat.connect_start = jiffies; 7821b092092STrond Myklebust xprt->ops->connect(xprt, task); 7831da177e4SLinus Torvalds } 784718ba5b8STrond Myklebust xprt_release_write(xprt, task); 7851da177e4SLinus Torvalds } 7861da177e4SLinus Torvalds 7879903cd1cSChuck Lever static void xprt_connect_status(struct rpc_task *task) 7881da177e4SLinus Torvalds { 789ad2368d6STrond Myklebust struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; 7901da177e4SLinus Torvalds 791cd983ef8SChuck Lever if (task->tk_status == 0) { 792262ca07dSChuck Lever xprt->stat.connect_count++; 793262ca07dSChuck Lever xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start; 79446121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: connection established\n", 7951da177e4SLinus Torvalds task->tk_pid); 7961da177e4SLinus Torvalds return; 7971da177e4SLinus Torvalds } 7981da177e4SLinus Torvalds 7991da177e4SLinus Torvalds switch (task->tk_status) { 8000fe8d04eSTrond Myklebust case -ECONNREFUSED: 8010fe8d04eSTrond Myklebust case -ECONNRESET: 8020fe8d04eSTrond Myklebust case -ECONNABORTED: 8030fe8d04eSTrond Myklebust case -ENETUNREACH: 8040fe8d04eSTrond Myklebust case -EHOSTUNREACH: 8052fc193cfSTrond Myklebust case -EPIPE: 8062a491991STrond Myklebust case -EAGAIN: 8072a491991STrond Myklebust dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid); 80823475d66SChuck Lever break; 8091da177e4SLinus Torvalds case -ETIMEDOUT: 81046121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: connect attempt timed " 81146121cf7SChuck Lever "out\n", task->tk_pid); 8121da177e4SLinus Torvalds break; 8131da177e4SLinus Torvalds default: 81446121cf7SChuck Lever dprintk("RPC: %5u xprt_connect_status: error %d connecting to " 81546121cf7SChuck Lever "server %s\n", task->tk_pid, -task->tk_status, 8164e0038b6STrond Myklebust xprt->servername); 81723475d66SChuck Lever task->tk_status = -EIO; 81823475d66SChuck Lever } 8191da177e4SLinus Torvalds } 8201da177e4SLinus Torvalds 8219903cd1cSChuck Lever /** 8229903cd1cSChuck Lever * xprt_lookup_rqst - find an RPC request corresponding to an XID 8239903cd1cSChuck Lever * @xprt: transport on which the original request was transmitted 8249903cd1cSChuck Lever * @xid: RPC XID of incoming reply 8259903cd1cSChuck Lever * 8261da177e4SLinus Torvalds */ 827d8ed029dSAlexey Dobriyan struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid) 8281da177e4SLinus Torvalds { 8298f3a6de3SPavel Emelyanov struct rpc_rqst *entry; 8301da177e4SLinus Torvalds 8318f3a6de3SPavel Emelyanov list_for_each_entry(entry, &xprt->recv, rq_list) 8323705ad64SJeff Layton if (entry->rq_xid == xid) { 8333705ad64SJeff Layton trace_xprt_lookup_rqst(xprt, xid, 0); 834262ca07dSChuck Lever return entry; 8353705ad64SJeff Layton } 83646121cf7SChuck Lever 83746121cf7SChuck Lever dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n", 83846121cf7SChuck Lever ntohl(xid)); 8393705ad64SJeff Layton trace_xprt_lookup_rqst(xprt, xid, -ENOENT); 840262ca07dSChuck Lever xprt->stat.bad_xids++; 841262ca07dSChuck Lever return NULL; 8421da177e4SLinus Torvalds } 84312444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_lookup_rqst); 8441da177e4SLinus Torvalds 845bbc72ceaSChuck Lever static void xprt_update_rtt(struct rpc_task *task) 8461da177e4SLinus Torvalds { 8471570c1e4SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 8481570c1e4SChuck Lever struct rpc_rtt *rtt = task->tk_client->cl_rtt; 84995c96174SEric Dumazet unsigned int timer = task->tk_msg.rpc_proc->p_timer; 850d60dbb20STrond Myklebust long m = usecs_to_jiffies(ktime_to_us(req->rq_rtt)); 8511570c1e4SChuck Lever 8521da177e4SLinus Torvalds if (timer) { 8531da177e4SLinus Torvalds if (req->rq_ntrans == 1) 854ff839970SChuck Lever rpc_update_rtt(rtt, timer, m); 8551570c1e4SChuck Lever rpc_set_timeo(rtt, timer, req->rq_ntrans - 1); 8561da177e4SLinus Torvalds } 8571da177e4SLinus Torvalds } 8581da177e4SLinus Torvalds 8591570c1e4SChuck Lever /** 8601570c1e4SChuck Lever * xprt_complete_rqst - called when reply processing is complete 8611570c1e4SChuck Lever * @task: RPC request that recently completed 8621570c1e4SChuck Lever * @copied: actual number of bytes received from the transport 8631570c1e4SChuck Lever * 8641570c1e4SChuck Lever * Caller holds transport lock. 8651570c1e4SChuck Lever */ 8661570c1e4SChuck Lever void xprt_complete_rqst(struct rpc_task *task, int copied) 8671570c1e4SChuck Lever { 8681570c1e4SChuck Lever struct rpc_rqst *req = task->tk_rqstp; 869fda13939STrond Myklebust struct rpc_xprt *xprt = req->rq_xprt; 8701da177e4SLinus Torvalds 8711570c1e4SChuck Lever dprintk("RPC: %5u xid %08x complete (%d bytes received)\n", 8721570c1e4SChuck Lever task->tk_pid, ntohl(req->rq_xid), copied); 8733705ad64SJeff Layton trace_xprt_complete_rqst(xprt, req->rq_xid, copied); 8741da177e4SLinus Torvalds 875fda13939STrond Myklebust xprt->stat.recvs++; 876d60dbb20STrond Myklebust req->rq_rtt = ktime_sub(ktime_get(), req->rq_xtime); 877bbc72ceaSChuck Lever if (xprt->ops->timer != NULL) 878bbc72ceaSChuck Lever xprt_update_rtt(task); 879ef759a2eSChuck Lever 8801da177e4SLinus Torvalds list_del_init(&req->rq_list); 8811e799b67STrond Myklebust req->rq_private_buf.len = copied; 882dd2b63d0SRicardo Labiaga /* Ensure all writes are done before we update */ 883dd2b63d0SRicardo Labiaga /* req->rq_reply_bytes_recvd */ 88443ac3f29STrond Myklebust smp_wmb(); 885dd2b63d0SRicardo Labiaga req->rq_reply_bytes_recvd = copied; 886fda13939STrond Myklebust rpc_wake_up_queued_task(&xprt->pending, task); 8871da177e4SLinus Torvalds } 88812444809S\"Talpey, Thomas\ EXPORT_SYMBOL_GPL(xprt_complete_rqst); 8891da177e4SLinus Torvalds 89046c0ee8bSChuck Lever static void xprt_timer(struct rpc_task *task) 8911da177e4SLinus Torvalds { 8921da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 8931da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 8941da177e4SLinus Torvalds 8955d00837bSTrond Myklebust if (task->tk_status != -ETIMEDOUT) 8965d00837bSTrond Myklebust return; 89746121cf7SChuck Lever dprintk("RPC: %5u xprt_timer\n", task->tk_pid); 89846c0ee8bSChuck Lever 8995d00837bSTrond Myklebust spin_lock_bh(&xprt->transport_lock); 900dd2b63d0SRicardo Labiaga if (!req->rq_reply_bytes_recvd) { 90146c0ee8bSChuck Lever if (xprt->ops->timer) 9026a24dfb6STrond Myklebust xprt->ops->timer(xprt, task); 9035d00837bSTrond Myklebust } else 9045d00837bSTrond Myklebust task->tk_status = 0; 9055d00837bSTrond Myklebust spin_unlock_bh(&xprt->transport_lock); 9061da177e4SLinus Torvalds } 9071da177e4SLinus Torvalds 9089903cd1cSChuck Lever /** 9099903cd1cSChuck Lever * xprt_prepare_transmit - reserve the transport before sending a request 9109903cd1cSChuck Lever * @task: RPC task about to send a request 9119903cd1cSChuck Lever * 9121da177e4SLinus Torvalds */ 91390051ea7STrond Myklebust bool xprt_prepare_transmit(struct rpc_task *task) 9141da177e4SLinus Torvalds { 9151da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 9161da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 91790051ea7STrond Myklebust bool ret = false; 9181da177e4SLinus Torvalds 91946121cf7SChuck Lever dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid); 9201da177e4SLinus Torvalds 9214a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 9228a19a0b6STrond Myklebust if (!req->rq_bytes_sent) { 9238a19a0b6STrond Myklebust if (req->rq_reply_bytes_recvd) { 92490051ea7STrond Myklebust task->tk_status = req->rq_reply_bytes_recvd; 9251da177e4SLinus Torvalds goto out_unlock; 9261da177e4SLinus Torvalds } 9278a19a0b6STrond Myklebust if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) 9288a19a0b6STrond Myklebust && xprt_connected(xprt) 9298a19a0b6STrond Myklebust && req->rq_connect_cookie == xprt->connect_cookie) { 9308a19a0b6STrond Myklebust xprt->ops->set_retrans_timeout(task); 9318a19a0b6STrond Myklebust rpc_sleep_on(&xprt->pending, task, xprt_timer); 9328a19a0b6STrond Myklebust goto out_unlock; 9338a19a0b6STrond Myklebust } 9348a19a0b6STrond Myklebust } 93590051ea7STrond Myklebust if (!xprt->ops->reserve_xprt(xprt, task)) { 93690051ea7STrond Myklebust task->tk_status = -EAGAIN; 93790051ea7STrond Myklebust goto out_unlock; 93890051ea7STrond Myklebust } 93990051ea7STrond Myklebust ret = true; 9401da177e4SLinus Torvalds out_unlock: 9414a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 94290051ea7STrond Myklebust return ret; 9431da177e4SLinus Torvalds } 9441da177e4SLinus Torvalds 945e0ab53deSTrond Myklebust void xprt_end_transmit(struct rpc_task *task) 9465e5ce5beSTrond Myklebust { 947343952faSRahul Iyer xprt_release_write(task->tk_rqstp->rq_xprt, task); 9485e5ce5beSTrond Myklebust } 9495e5ce5beSTrond Myklebust 9509903cd1cSChuck Lever /** 9519903cd1cSChuck Lever * xprt_transmit - send an RPC request on a transport 9529903cd1cSChuck Lever * @task: controlling RPC task 9539903cd1cSChuck Lever * 9549903cd1cSChuck Lever * We have to copy the iovec because sendmsg fiddles with its contents. 9559903cd1cSChuck Lever */ 9569903cd1cSChuck Lever void xprt_transmit(struct rpc_task *task) 9571da177e4SLinus Torvalds { 9581da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 9591da177e4SLinus Torvalds struct rpc_xprt *xprt = req->rq_xprt; 96015a45206SAndy Adamson int status, numreqs; 9611da177e4SLinus Torvalds 96246121cf7SChuck Lever dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen); 9631da177e4SLinus Torvalds 964dd2b63d0SRicardo Labiaga if (!req->rq_reply_bytes_recvd) { 96555ae1aabSRicardo Labiaga if (list_empty(&req->rq_list) && rpc_reply_expected(task)) { 96655ae1aabSRicardo Labiaga /* 96755ae1aabSRicardo Labiaga * Add to the list only if we're expecting a reply 96855ae1aabSRicardo Labiaga */ 9694a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 9701da177e4SLinus Torvalds /* Update the softirq receive buffer */ 9711da177e4SLinus Torvalds memcpy(&req->rq_private_buf, &req->rq_rcv_buf, 9721da177e4SLinus Torvalds sizeof(req->rq_private_buf)); 9731da177e4SLinus Torvalds /* Add request to the receive list */ 9741da177e4SLinus Torvalds list_add_tail(&req->rq_list, &xprt->recv); 9754a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 9761da177e4SLinus Torvalds xprt_reset_majortimeo(req); 9770f9dc2b1STrond Myklebust /* Turn off autodisconnect */ 9780f9dc2b1STrond Myklebust del_singleshot_timer_sync(&xprt->timer); 9791da177e4SLinus Torvalds } 9801da177e4SLinus Torvalds } else if (!req->rq_bytes_sent) 9811da177e4SLinus Torvalds return; 9821da177e4SLinus Torvalds 983ff839970SChuck Lever req->rq_xtime = ktime_get(); 984a246b010SChuck Lever status = xprt->ops->send_request(task); 9853705ad64SJeff Layton trace_xprt_transmit(xprt, req->rq_xid, status); 986c8485e4dSTrond Myklebust if (status != 0) { 987c8485e4dSTrond Myklebust task->tk_status = status; 988c8485e4dSTrond Myklebust return; 989c8485e4dSTrond Myklebust } 9904a068258SChuck Lever xprt_inject_disconnect(xprt); 991c8485e4dSTrond Myklebust 99246121cf7SChuck Lever dprintk("RPC: %5u xmit complete\n", task->tk_pid); 993468f8613SBryan Schumaker task->tk_flags |= RPC_TASK_SENT; 994fe3aca29SChuck Lever spin_lock_bh(&xprt->transport_lock); 995262ca07dSChuck Lever 996fe3aca29SChuck Lever xprt->ops->set_retrans_timeout(task); 997262ca07dSChuck Lever 99815a45206SAndy Adamson numreqs = atomic_read(&xprt->num_reqs); 99915a45206SAndy Adamson if (numreqs > xprt->stat.max_slots) 100015a45206SAndy Adamson xprt->stat.max_slots = numreqs; 1001262ca07dSChuck Lever xprt->stat.sends++; 1002262ca07dSChuck Lever xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs; 1003262ca07dSChuck Lever xprt->stat.bklog_u += xprt->backlog.qlen; 100415a45206SAndy Adamson xprt->stat.sending_u += xprt->sending.qlen; 100515a45206SAndy Adamson xprt->stat.pending_u += xprt->pending.qlen; 1006262ca07dSChuck Lever 1007fe3aca29SChuck Lever /* Don't race with disconnect */ 1008fe3aca29SChuck Lever if (!xprt_connected(xprt)) 1009fe3aca29SChuck Lever task->tk_status = -ENOTCONN; 10100a660521STrond Myklebust else { 101155ae1aabSRicardo Labiaga /* 101255ae1aabSRicardo Labiaga * Sleep on the pending queue since 101355ae1aabSRicardo Labiaga * we're expecting a reply. 101455ae1aabSRicardo Labiaga */ 10150a660521STrond Myklebust if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task)) 10165d00837bSTrond Myklebust rpc_sleep_on(&xprt->pending, task, xprt_timer); 10170a660521STrond Myklebust req->rq_connect_cookie = xprt->connect_cookie; 101855ae1aabSRicardo Labiaga } 1019fe3aca29SChuck Lever spin_unlock_bh(&xprt->transport_lock); 10201da177e4SLinus Torvalds } 10211da177e4SLinus Torvalds 1022ba60eb25STrond Myklebust static void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task) 1023ba60eb25STrond Myklebust { 1024ba60eb25STrond Myklebust set_bit(XPRT_CONGESTED, &xprt->state); 1025ba60eb25STrond Myklebust rpc_sleep_on(&xprt->backlog, task, NULL); 1026ba60eb25STrond Myklebust } 1027ba60eb25STrond Myklebust 1028ba60eb25STrond Myklebust static void xprt_wake_up_backlog(struct rpc_xprt *xprt) 1029ba60eb25STrond Myklebust { 1030ba60eb25STrond Myklebust if (rpc_wake_up_next(&xprt->backlog) == NULL) 1031ba60eb25STrond Myklebust clear_bit(XPRT_CONGESTED, &xprt->state); 1032ba60eb25STrond Myklebust } 1033ba60eb25STrond Myklebust 1034ba60eb25STrond Myklebust static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task) 1035ba60eb25STrond Myklebust { 1036ba60eb25STrond Myklebust bool ret = false; 1037ba60eb25STrond Myklebust 1038ba60eb25STrond Myklebust if (!test_bit(XPRT_CONGESTED, &xprt->state)) 1039ba60eb25STrond Myklebust goto out; 1040ba60eb25STrond Myklebust spin_lock(&xprt->reserve_lock); 1041ba60eb25STrond Myklebust if (test_bit(XPRT_CONGESTED, &xprt->state)) { 1042ba60eb25STrond Myklebust rpc_sleep_on(&xprt->backlog, task, NULL); 1043ba60eb25STrond Myklebust ret = true; 1044ba60eb25STrond Myklebust } 1045ba60eb25STrond Myklebust spin_unlock(&xprt->reserve_lock); 1046ba60eb25STrond Myklebust out: 1047ba60eb25STrond Myklebust return ret; 1048ba60eb25STrond Myklebust } 1049ba60eb25STrond Myklebust 1050d9ba131dSTrond Myklebust static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt, gfp_t gfp_flags) 1051d9ba131dSTrond Myklebust { 1052d9ba131dSTrond Myklebust struct rpc_rqst *req = ERR_PTR(-EAGAIN); 1053d9ba131dSTrond Myklebust 1054d9ba131dSTrond Myklebust if (!atomic_add_unless(&xprt->num_reqs, 1, xprt->max_reqs)) 1055d9ba131dSTrond Myklebust goto out; 1056d9ba131dSTrond Myklebust req = kzalloc(sizeof(struct rpc_rqst), gfp_flags); 1057d9ba131dSTrond Myklebust if (req != NULL) 1058d9ba131dSTrond Myklebust goto out; 1059d9ba131dSTrond Myklebust atomic_dec(&xprt->num_reqs); 1060d9ba131dSTrond Myklebust req = ERR_PTR(-ENOMEM); 1061d9ba131dSTrond Myklebust out: 1062d9ba131dSTrond Myklebust return req; 1063d9ba131dSTrond Myklebust } 1064d9ba131dSTrond Myklebust 1065d9ba131dSTrond Myklebust static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) 1066d9ba131dSTrond Myklebust { 1067d9ba131dSTrond Myklebust if (atomic_add_unless(&xprt->num_reqs, -1, xprt->min_reqs)) { 1068d9ba131dSTrond Myklebust kfree(req); 1069d9ba131dSTrond Myklebust return true; 1070d9ba131dSTrond Myklebust } 1071d9ba131dSTrond Myklebust return false; 1072d9ba131dSTrond Myklebust } 1073d9ba131dSTrond Myklebust 1074f39c1bfbSTrond Myklebust void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) 10751da177e4SLinus Torvalds { 1076d9ba131dSTrond Myklebust struct rpc_rqst *req; 10771da177e4SLinus Torvalds 1078f39c1bfbSTrond Myklebust spin_lock(&xprt->reserve_lock); 10791da177e4SLinus Torvalds if (!list_empty(&xprt->free)) { 1080d9ba131dSTrond Myklebust req = list_entry(xprt->free.next, struct rpc_rqst, rq_list); 1081d9ba131dSTrond Myklebust list_del(&req->rq_list); 1082d9ba131dSTrond Myklebust goto out_init_req; 1083d9ba131dSTrond Myklebust } 10846b343099SJeff Layton req = xprt_dynamic_alloc_slot(xprt, GFP_NOWAIT|__GFP_NOWARN); 1085d9ba131dSTrond Myklebust if (!IS_ERR(req)) 1086d9ba131dSTrond Myklebust goto out_init_req; 1087d9ba131dSTrond Myklebust switch (PTR_ERR(req)) { 1088d9ba131dSTrond Myklebust case -ENOMEM: 1089d9ba131dSTrond Myklebust dprintk("RPC: dynamic allocation of request slot " 1090d9ba131dSTrond Myklebust "failed! Retrying\n"); 10911afeaf5cSTrond Myklebust task->tk_status = -ENOMEM; 1092d9ba131dSTrond Myklebust break; 1093d9ba131dSTrond Myklebust case -EAGAIN: 1094ba60eb25STrond Myklebust xprt_add_backlog(xprt, task); 1095d9ba131dSTrond Myklebust dprintk("RPC: waiting for request slot\n"); 10961afeaf5cSTrond Myklebust default: 1097d9ba131dSTrond Myklebust task->tk_status = -EAGAIN; 10981afeaf5cSTrond Myklebust } 1099f39c1bfbSTrond Myklebust spin_unlock(&xprt->reserve_lock); 1100d9ba131dSTrond Myklebust return; 1101d9ba131dSTrond Myklebust out_init_req: 1102d9ba131dSTrond Myklebust task->tk_status = 0; 11031da177e4SLinus Torvalds task->tk_rqstp = req; 11041da177e4SLinus Torvalds xprt_request_init(task, xprt); 1105f39c1bfbSTrond Myklebust spin_unlock(&xprt->reserve_lock); 11061da177e4SLinus Torvalds } 1107f39c1bfbSTrond Myklebust EXPORT_SYMBOL_GPL(xprt_alloc_slot); 1108f39c1bfbSTrond Myklebust 1109f39c1bfbSTrond Myklebust void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) 1110f39c1bfbSTrond Myklebust { 1111f39c1bfbSTrond Myklebust /* Note: grabbing the xprt_lock_write() ensures that we throttle 1112f39c1bfbSTrond Myklebust * new slot allocation if the transport is congested (i.e. when 1113f39c1bfbSTrond Myklebust * reconnecting a stream transport or when out of socket write 1114f39c1bfbSTrond Myklebust * buffer space). 1115f39c1bfbSTrond Myklebust */ 1116f39c1bfbSTrond Myklebust if (xprt_lock_write(xprt, task)) { 1117f39c1bfbSTrond Myklebust xprt_alloc_slot(xprt, task); 1118f39c1bfbSTrond Myklebust xprt_release_write(xprt, task); 1119f39c1bfbSTrond Myklebust } 1120f39c1bfbSTrond Myklebust } 1121f39c1bfbSTrond Myklebust EXPORT_SYMBOL_GPL(xprt_lock_and_alloc_slot); 11221da177e4SLinus Torvalds 1123ee5ebe85STrond Myklebust static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) 1124ee5ebe85STrond Myklebust { 1125ee5ebe85STrond Myklebust spin_lock(&xprt->reserve_lock); 1126c25573b5STrond Myklebust if (!xprt_dynamic_free_slot(xprt, req)) { 1127c25573b5STrond Myklebust memset(req, 0, sizeof(*req)); /* mark unused */ 1128ee5ebe85STrond Myklebust list_add(&req->rq_list, &xprt->free); 1129c25573b5STrond Myklebust } 1130ba60eb25STrond Myklebust xprt_wake_up_backlog(xprt); 1131ee5ebe85STrond Myklebust spin_unlock(&xprt->reserve_lock); 1132ee5ebe85STrond Myklebust } 1133ee5ebe85STrond Myklebust 113421de0a95STrond Myklebust static void xprt_free_all_slots(struct rpc_xprt *xprt) 113521de0a95STrond Myklebust { 113621de0a95STrond Myklebust struct rpc_rqst *req; 113721de0a95STrond Myklebust while (!list_empty(&xprt->free)) { 113821de0a95STrond Myklebust req = list_first_entry(&xprt->free, struct rpc_rqst, rq_list); 113921de0a95STrond Myklebust list_del(&req->rq_list); 114021de0a95STrond Myklebust kfree(req); 114121de0a95STrond Myklebust } 114221de0a95STrond Myklebust } 114321de0a95STrond Myklebust 1144d9ba131dSTrond Myklebust struct rpc_xprt *xprt_alloc(struct net *net, size_t size, 1145d9ba131dSTrond Myklebust unsigned int num_prealloc, 1146d9ba131dSTrond Myklebust unsigned int max_alloc) 1147bd1722d4SPavel Emelyanov { 1148bd1722d4SPavel Emelyanov struct rpc_xprt *xprt; 114921de0a95STrond Myklebust struct rpc_rqst *req; 115021de0a95STrond Myklebust int i; 1151bd1722d4SPavel Emelyanov 1152bd1722d4SPavel Emelyanov xprt = kzalloc(size, GFP_KERNEL); 1153bd1722d4SPavel Emelyanov if (xprt == NULL) 1154bd1722d4SPavel Emelyanov goto out; 1155bd1722d4SPavel Emelyanov 115621de0a95STrond Myklebust xprt_init(xprt, net); 115721de0a95STrond Myklebust 115821de0a95STrond Myklebust for (i = 0; i < num_prealloc; i++) { 115921de0a95STrond Myklebust req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL); 116021de0a95STrond Myklebust if (!req) 11618313164cSwangweidong goto out_free; 116221de0a95STrond Myklebust list_add(&req->rq_list, &xprt->free); 116321de0a95STrond Myklebust } 1164d9ba131dSTrond Myklebust if (max_alloc > num_prealloc) 1165d9ba131dSTrond Myklebust xprt->max_reqs = max_alloc; 1166d9ba131dSTrond Myklebust else 116721de0a95STrond Myklebust xprt->max_reqs = num_prealloc; 1168d9ba131dSTrond Myklebust xprt->min_reqs = num_prealloc; 1169d9ba131dSTrond Myklebust atomic_set(&xprt->num_reqs, num_prealloc); 1170bd1722d4SPavel Emelyanov 1171bd1722d4SPavel Emelyanov return xprt; 1172bd1722d4SPavel Emelyanov 1173bd1722d4SPavel Emelyanov out_free: 117421de0a95STrond Myklebust xprt_free(xprt); 1175bd1722d4SPavel Emelyanov out: 1176bd1722d4SPavel Emelyanov return NULL; 1177bd1722d4SPavel Emelyanov } 1178bd1722d4SPavel Emelyanov EXPORT_SYMBOL_GPL(xprt_alloc); 1179bd1722d4SPavel Emelyanov 1180e204e621SPavel Emelyanov void xprt_free(struct rpc_xprt *xprt) 1181e204e621SPavel Emelyanov { 118237aa2133SPavel Emelyanov put_net(xprt->xprt_net); 118321de0a95STrond Myklebust xprt_free_all_slots(xprt); 1184fda1bfefSTrond Myklebust kfree_rcu(xprt, rcu); 1185e204e621SPavel Emelyanov } 1186e204e621SPavel Emelyanov EXPORT_SYMBOL_GPL(xprt_free); 1187e204e621SPavel Emelyanov 11889903cd1cSChuck Lever /** 11899903cd1cSChuck Lever * xprt_reserve - allocate an RPC request slot 11909903cd1cSChuck Lever * @task: RPC task requesting a slot allocation 11919903cd1cSChuck Lever * 1192ba60eb25STrond Myklebust * If the transport is marked as being congested, or if no more 1193ba60eb25STrond Myklebust * slots are available, place the task on the transport's 11949903cd1cSChuck Lever * backlog queue. 11959903cd1cSChuck Lever */ 11969903cd1cSChuck Lever void xprt_reserve(struct rpc_task *task) 11971da177e4SLinus Torvalds { 1198fb43d172STrond Myklebust struct rpc_xprt *xprt = task->tk_xprt; 11991da177e4SLinus Torvalds 120043cedbf0STrond Myklebust task->tk_status = 0; 120143cedbf0STrond Myklebust if (task->tk_rqstp != NULL) 120243cedbf0STrond Myklebust return; 120343cedbf0STrond Myklebust 120443cedbf0STrond Myklebust task->tk_timeout = 0; 120543cedbf0STrond Myklebust task->tk_status = -EAGAIN; 1206ba60eb25STrond Myklebust if (!xprt_throttle_congested(xprt, task)) 1207ba60eb25STrond Myklebust xprt->ops->alloc_slot(xprt, task); 1208ba60eb25STrond Myklebust } 1209ba60eb25STrond Myklebust 1210ba60eb25STrond Myklebust /** 1211ba60eb25STrond Myklebust * xprt_retry_reserve - allocate an RPC request slot 1212ba60eb25STrond Myklebust * @task: RPC task requesting a slot allocation 1213ba60eb25STrond Myklebust * 1214ba60eb25STrond Myklebust * If no more slots are available, place the task on the transport's 1215ba60eb25STrond Myklebust * backlog queue. 1216ba60eb25STrond Myklebust * Note that the only difference with xprt_reserve is that we now 1217ba60eb25STrond Myklebust * ignore the value of the XPRT_CONGESTED flag. 1218ba60eb25STrond Myklebust */ 1219ba60eb25STrond Myklebust void xprt_retry_reserve(struct rpc_task *task) 1220ba60eb25STrond Myklebust { 1221fb43d172STrond Myklebust struct rpc_xprt *xprt = task->tk_xprt; 1222ba60eb25STrond Myklebust 1223ba60eb25STrond Myklebust task->tk_status = 0; 1224ba60eb25STrond Myklebust if (task->tk_rqstp != NULL) 1225ba60eb25STrond Myklebust return; 1226ba60eb25STrond Myklebust 1227ba60eb25STrond Myklebust task->tk_timeout = 0; 1228ba60eb25STrond Myklebust task->tk_status = -EAGAIN; 1229f39c1bfbSTrond Myklebust xprt->ops->alloc_slot(xprt, task); 12301da177e4SLinus Torvalds } 12311da177e4SLinus Torvalds 1232d8ed029dSAlexey Dobriyan static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt) 12331da177e4SLinus Torvalds { 12340eae88f3SEric Dumazet return (__force __be32)xprt->xid++; 12351da177e4SLinus Torvalds } 12361da177e4SLinus Torvalds 12371da177e4SLinus Torvalds static inline void xprt_init_xid(struct rpc_xprt *xprt) 12381da177e4SLinus Torvalds { 123963862b5bSAruna-Hewapathirane xprt->xid = prandom_u32(); 12401da177e4SLinus Torvalds } 12411da177e4SLinus Torvalds 12429903cd1cSChuck Lever static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) 12431da177e4SLinus Torvalds { 12441da177e4SLinus Torvalds struct rpc_rqst *req = task->tk_rqstp; 12451da177e4SLinus Torvalds 1246d9ba131dSTrond Myklebust INIT_LIST_HEAD(&req->rq_list); 1247ba7392bbSTrond Myklebust req->rq_timeout = task->tk_client->cl_timeout->to_initval; 12481da177e4SLinus Torvalds req->rq_task = task; 12491da177e4SLinus Torvalds req->rq_xprt = xprt; 125002107148SChuck Lever req->rq_buffer = NULL; 12511da177e4SLinus Torvalds req->rq_xid = xprt_alloc_xid(xprt); 12520a660521STrond Myklebust req->rq_connect_cookie = xprt->connect_cookie - 1; 125392551948STrond Myklebust req->rq_bytes_sent = 0; 125492551948STrond Myklebust req->rq_snd_buf.len = 0; 125592551948STrond Myklebust req->rq_snd_buf.buflen = 0; 125692551948STrond Myklebust req->rq_rcv_buf.len = 0; 125792551948STrond Myklebust req->rq_rcv_buf.buflen = 0; 1258ead5e1c2SJ. Bruce Fields req->rq_release_snd_buf = NULL; 1259da45828eSTrond Myklebust xprt_reset_majortimeo(req); 126046121cf7SChuck Lever dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid, 12611da177e4SLinus Torvalds req, ntohl(req->rq_xid)); 12621da177e4SLinus Torvalds } 12631da177e4SLinus Torvalds 12649903cd1cSChuck Lever /** 12659903cd1cSChuck Lever * xprt_release - release an RPC request slot 12669903cd1cSChuck Lever * @task: task which is finished with the slot 12679903cd1cSChuck Lever * 12681da177e4SLinus Torvalds */ 12699903cd1cSChuck Lever void xprt_release(struct rpc_task *task) 12701da177e4SLinus Torvalds { 127155ae1aabSRicardo Labiaga struct rpc_xprt *xprt; 127287ed5003STrond Myklebust struct rpc_rqst *req = task->tk_rqstp; 12731da177e4SLinus Torvalds 127487ed5003STrond Myklebust if (req == NULL) { 127587ed5003STrond Myklebust if (task->tk_client) { 1276fb43d172STrond Myklebust xprt = task->tk_xprt; 127787ed5003STrond Myklebust if (xprt->snd_task == task) 127887ed5003STrond Myklebust xprt_release_write(xprt, task); 127987ed5003STrond Myklebust } 12801da177e4SLinus Torvalds return; 128187ed5003STrond Myklebust } 128255ae1aabSRicardo Labiaga 128355ae1aabSRicardo Labiaga xprt = req->rq_xprt; 12840a702195SWeston Andros Adamson if (task->tk_ops->rpc_count_stats != NULL) 12850a702195SWeston Andros Adamson task->tk_ops->rpc_count_stats(task, task->tk_calldata); 12860a702195SWeston Andros Adamson else if (task->tk_client) 12870a702195SWeston Andros Adamson rpc_count_iostats(task, task->tk_client->cl_metrics); 12884a0f8c04SChuck Lever spin_lock_bh(&xprt->transport_lock); 128949e9a890SChuck Lever xprt->ops->release_xprt(xprt, task); 1290a58dd398SChuck Lever if (xprt->ops->release_request) 1291a58dd398SChuck Lever xprt->ops->release_request(task); 12921da177e4SLinus Torvalds if (!list_empty(&req->rq_list)) 12931da177e4SLinus Torvalds list_del(&req->rq_list); 12941da177e4SLinus Torvalds xprt->last_used = jiffies; 1295ad3331acSTrond Myklebust xprt_schedule_autodisconnect(xprt); 12964a0f8c04SChuck Lever spin_unlock_bh(&xprt->transport_lock); 1297ee5ebe85STrond Myklebust if (req->rq_buffer) 1298c5a4dd8bSChuck Lever xprt->ops->buf_free(req->rq_buffer); 12994a068258SChuck Lever xprt_inject_disconnect(xprt); 1300a17c2153STrond Myklebust if (req->rq_cred != NULL) 1301a17c2153STrond Myklebust put_rpccred(req->rq_cred); 13021da177e4SLinus Torvalds task->tk_rqstp = NULL; 1303ead5e1c2SJ. Bruce Fields if (req->rq_release_snd_buf) 1304ead5e1c2SJ. Bruce Fields req->rq_release_snd_buf(req); 130555ae1aabSRicardo Labiaga 130646121cf7SChuck Lever dprintk("RPC: %5u release request %p\n", task->tk_pid, req); 1307ee5ebe85STrond Myklebust if (likely(!bc_prealloc(req))) 1308ee5ebe85STrond Myklebust xprt_free_slot(xprt, req); 1309ee5ebe85STrond Myklebust else 1310c9acb42eSTrond Myklebust xprt_free_bc_request(req); 13111da177e4SLinus Torvalds } 13121da177e4SLinus Torvalds 131321de0a95STrond Myklebust static void xprt_init(struct rpc_xprt *xprt, struct net *net) 1314c2866763SChuck Lever { 131530c5116bSTrond Myklebust kref_init(&xprt->kref); 1316c2866763SChuck Lever 1317c2866763SChuck Lever spin_lock_init(&xprt->transport_lock); 1318c2866763SChuck Lever spin_lock_init(&xprt->reserve_lock); 1319c2866763SChuck Lever 1320c2866763SChuck Lever INIT_LIST_HEAD(&xprt->free); 1321c2866763SChuck Lever INIT_LIST_HEAD(&xprt->recv); 13229e00abc3STrond Myklebust #if defined(CONFIG_SUNRPC_BACKCHANNEL) 1323f9acac1aSRicardo Labiaga spin_lock_init(&xprt->bc_pa_lock); 1324f9acac1aSRicardo Labiaga INIT_LIST_HEAD(&xprt->bc_pa_list); 13259e00abc3STrond Myklebust #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 132680b14d5eSTrond Myklebust INIT_LIST_HEAD(&xprt->xprt_switch); 1327f9acac1aSRicardo Labiaga 1328c2866763SChuck Lever xprt->last_used = jiffies; 1329c2866763SChuck Lever xprt->cwnd = RPC_INITCWND; 1330a509050bSChuck Lever xprt->bind_index = 0; 1331c2866763SChuck Lever 1332c2866763SChuck Lever rpc_init_wait_queue(&xprt->binding, "xprt_binding"); 1333c2866763SChuck Lever rpc_init_wait_queue(&xprt->pending, "xprt_pending"); 133434006ceeSTrond Myklebust rpc_init_priority_wait_queue(&xprt->sending, "xprt_sending"); 1335c2866763SChuck Lever rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog"); 1336c2866763SChuck Lever 1337c2866763SChuck Lever xprt_init_xid(xprt); 1338c2866763SChuck Lever 133921de0a95STrond Myklebust xprt->xprt_net = get_net(net); 13408d9266ffSTrond Myklebust } 13418d9266ffSTrond Myklebust 13428d9266ffSTrond Myklebust /** 13438d9266ffSTrond Myklebust * xprt_create_transport - create an RPC transport 13448d9266ffSTrond Myklebust * @args: rpc transport creation arguments 13458d9266ffSTrond Myklebust * 13468d9266ffSTrond Myklebust */ 13478d9266ffSTrond Myklebust struct rpc_xprt *xprt_create_transport(struct xprt_create *args) 13488d9266ffSTrond Myklebust { 13498d9266ffSTrond Myklebust struct rpc_xprt *xprt; 13508d9266ffSTrond Myklebust struct xprt_class *t; 13518d9266ffSTrond Myklebust 13528d9266ffSTrond Myklebust spin_lock(&xprt_list_lock); 13538d9266ffSTrond Myklebust list_for_each_entry(t, &xprt_list, list) { 13548d9266ffSTrond Myklebust if (t->ident == args->ident) { 13558d9266ffSTrond Myklebust spin_unlock(&xprt_list_lock); 13568d9266ffSTrond Myklebust goto found; 13578d9266ffSTrond Myklebust } 13588d9266ffSTrond Myklebust } 13598d9266ffSTrond Myklebust spin_unlock(&xprt_list_lock); 13603c45ddf8SChuck Lever dprintk("RPC: transport (%d) not supported\n", args->ident); 13618d9266ffSTrond Myklebust return ERR_PTR(-EIO); 13628d9266ffSTrond Myklebust 13638d9266ffSTrond Myklebust found: 13648d9266ffSTrond Myklebust xprt = t->setup(args); 13658d9266ffSTrond Myklebust if (IS_ERR(xprt)) { 13668d9266ffSTrond Myklebust dprintk("RPC: xprt_create_transport: failed, %ld\n", 13678d9266ffSTrond Myklebust -PTR_ERR(xprt)); 136821de0a95STrond Myklebust goto out; 13698d9266ffSTrond Myklebust } 137033d90ac0SJ. Bruce Fields if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT) 137133d90ac0SJ. Bruce Fields xprt->idle_timeout = 0; 137221de0a95STrond Myklebust INIT_WORK(&xprt->task_cleanup, xprt_autoclose); 137321de0a95STrond Myklebust if (xprt_has_timer(xprt)) 137421de0a95STrond Myklebust setup_timer(&xprt->timer, xprt_init_autodisconnect, 137521de0a95STrond Myklebust (unsigned long)xprt); 137621de0a95STrond Myklebust else 137721de0a95STrond Myklebust init_timer(&xprt->timer); 13784e0038b6STrond Myklebust 13794e0038b6STrond Myklebust if (strlen(args->servername) > RPC_MAXNETNAMELEN) { 13804e0038b6STrond Myklebust xprt_destroy(xprt); 13814e0038b6STrond Myklebust return ERR_PTR(-EINVAL); 13824e0038b6STrond Myklebust } 13834e0038b6STrond Myklebust xprt->servername = kstrdup(args->servername, GFP_KERNEL); 13844e0038b6STrond Myklebust if (xprt->servername == NULL) { 13854e0038b6STrond Myklebust xprt_destroy(xprt); 13864e0038b6STrond Myklebust return ERR_PTR(-ENOMEM); 13874e0038b6STrond Myklebust } 13884e0038b6STrond Myklebust 13893f940098SJeff Layton rpc_xprt_debugfs_register(xprt); 1390388f0c77SJeff Layton 1391c2866763SChuck Lever dprintk("RPC: created transport %p with %u slots\n", xprt, 1392c2866763SChuck Lever xprt->max_reqs); 139321de0a95STrond Myklebust out: 1394c2866763SChuck Lever return xprt; 1395c2866763SChuck Lever } 1396c2866763SChuck Lever 13979903cd1cSChuck Lever /** 13989903cd1cSChuck Lever * xprt_destroy - destroy an RPC transport, killing off all requests. 1399a8de240aSTrond Myklebust * @xprt: transport to destroy 14009903cd1cSChuck Lever * 14011da177e4SLinus Torvalds */ 1402a8de240aSTrond Myklebust static void xprt_destroy(struct rpc_xprt *xprt) 14031da177e4SLinus Torvalds { 14041da177e4SLinus Torvalds dprintk("RPC: destroying transport %p\n", xprt); 140579234c3dSTrond Myklebust 140679234c3dSTrond Myklebust /* Exclude transport connect/disconnect handlers */ 140779234c3dSTrond Myklebust wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_UNINTERRUPTIBLE); 140879234c3dSTrond Myklebust 14090065db32STrond Myklebust del_timer_sync(&xprt->timer); 1410c8541ecdSChuck Lever 1411388f0c77SJeff Layton rpc_xprt_debugfs_unregister(xprt); 1412f6a1cc89STrond Myklebust rpc_destroy_wait_queue(&xprt->binding); 1413f6a1cc89STrond Myklebust rpc_destroy_wait_queue(&xprt->pending); 1414f6a1cc89STrond Myklebust rpc_destroy_wait_queue(&xprt->sending); 1415f6a1cc89STrond Myklebust rpc_destroy_wait_queue(&xprt->backlog); 1416c3ae62aeSJ. Bruce Fields cancel_work_sync(&xprt->task_cleanup); 14174e0038b6STrond Myklebust kfree(xprt->servername); 1418c8541ecdSChuck Lever /* 1419c8541ecdSChuck Lever * Tear down transport state and free the rpc_xprt 1420c8541ecdSChuck Lever */ 1421a246b010SChuck Lever xprt->ops->destroy(xprt); 14226b6ca86bSTrond Myklebust } 14231da177e4SLinus Torvalds 142430c5116bSTrond Myklebust static void xprt_destroy_kref(struct kref *kref) 142530c5116bSTrond Myklebust { 142630c5116bSTrond Myklebust xprt_destroy(container_of(kref, struct rpc_xprt, kref)); 142730c5116bSTrond Myklebust } 142830c5116bSTrond Myklebust 142930c5116bSTrond Myklebust /** 143030c5116bSTrond Myklebust * xprt_get - return a reference to an RPC transport. 143130c5116bSTrond Myklebust * @xprt: pointer to the transport 143230c5116bSTrond Myklebust * 143330c5116bSTrond Myklebust */ 143430c5116bSTrond Myklebust struct rpc_xprt *xprt_get(struct rpc_xprt *xprt) 143530c5116bSTrond Myklebust { 143630c5116bSTrond Myklebust if (xprt != NULL && kref_get_unless_zero(&xprt->kref)) 143730c5116bSTrond Myklebust return xprt; 143830c5116bSTrond Myklebust return NULL; 143930c5116bSTrond Myklebust } 144030c5116bSTrond Myklebust EXPORT_SYMBOL_GPL(xprt_get); 144130c5116bSTrond Myklebust 14426b6ca86bSTrond Myklebust /** 14436b6ca86bSTrond Myklebust * xprt_put - release a reference to an RPC transport. 14446b6ca86bSTrond Myklebust * @xprt: pointer to the transport 14456b6ca86bSTrond Myklebust * 14466b6ca86bSTrond Myklebust */ 14476b6ca86bSTrond Myklebust void xprt_put(struct rpc_xprt *xprt) 14486b6ca86bSTrond Myklebust { 144930c5116bSTrond Myklebust if (xprt != NULL) 145030c5116bSTrond Myklebust kref_put(&xprt->kref, xprt_destroy_kref); 14516b6ca86bSTrond Myklebust } 14525d252f90SChuck Lever EXPORT_SYMBOL_GPL(xprt_put); 1453